Various grain conveying systems have been employed for transporting grain to and from grain storage bins or the like. Grain handling systems include both pneumatic conveyors and chain or related mechanical conveyors. In a typical tube-based system, grain to be conveyed is introduced into the system at a grain inlet, such as a pit or vacuum head. Downstream from the grain inlet the tubing system may be directed upwardly, for example, along the sidewall of a grain bin, and along the sloped, conical grain bin roof to a center grain opening in the grain bin roof. In a typical installation, a grain inlet may supply multiple grain bins and one or more discharge spouts are used to control the flow of grain within the system.
In one current chain and paddle conveyer system, a flow-through discharge spout includes a curved movable gate attached at an opening of a stationary tube section. The spout discharges when the movable gate is opened to allow grain to flow out of the tube section. The movable gate includes one or more gear racks driven by a pinion gear to open or close the gate. The movable gate may be manually operated or electrically controlled with an electric motor used to transition the gate between open and closed conditions. Limitations of the movable gate discharge spout include difficulty in manufacturing a closely-toleranced curved gate and operational difficulty as dust and debris tends to collect on the gate or gear rack which leads to increased friction and gate jamming. A need therefore exists for an improved discharge spout for a tube-based grain distribution system.